Simulation gridding method and apparatus including a structured areal gridder adapted for use by a reservoir simulator

A method of constructing a structured simulation grid adapted to be imposed on an earth formation and displaying said structured simulation grid, a horizon in said earth formation including a plurality of fault intersection lines, comprising the steps of:

• (a) enclosing a boundary around the fault intersection lines on the horizon;
• (b) building a triangulation and overlaying the triangulation over said boundary, said triangulation enclosing said boundary and said fault intersection lines within said boundary, the triangulation having nodes;
• (c) building a vector field having a plurality of directional vectors on the nodes of the triangulation, thereby producing a vectored triangulation, by assigning one of the directional vectors of the vector field to each node of the triangulation, each of the directional vectors having a direction;
• and
• (d) in response to the building step (c), producing said structured simulation grid and displaying said structured simulation grid.

A simulation gridding apparatus adapted for generating a set of more accurate grid block property information adapted for use by a simulator, a horizon in an earth formation including one or more fault intersection lines, comprising:

• a structured gridder adapted for generating a structured simulation grid, said structured gridder including,
• boundary enclosing means for enclosing a boundary around said fault intersection lines on said horizon,
• a structured areal gridder adapted for building a structured areal grid over said boundary after said fault intersection lines are enclosed by said boundary by said boundary enclosing means, said structured areal grid including intersecting streamlines, at least some of said streamlines including control lines, said control lines including said fault intersection lines, said intersecting streamlines including a plurality of nodes;
• and
• a block gridder adapted for connecting a plurality of coordinate lines to the plurality of nodes of said intersecting streamlines and dropping said plurality of coordinate lines into said earth formation until said coordinate lines intersect other horizons in said earth formation thereby producing a plurality of grid blocks of said structured simulation grid.

A program storage device readable by a machine, tangibly embodying a program of instructions executable by the machine to perform method steps for constructing a structured areal grid on a horizon in an earth formation, said method steps comprising:

• constructing said structured areal grid on said horizon in said earth formation, said horizon including a plurality of fault intersection lines, the step of constructing said structured areal grid on said horizon in said earth formation comprising the steps of,
• (a) enclosing a boundary around said plurality of fault intersection lines disposed on said horizon in said earth formation;
• (b) building a triangulation and overlaying said triangulation over said boundary, said triangulation enclosing said boundary and said fault intersection lines within said boundary, said triangulation having a plurality nodes;
• and
• (c) building a vector field including a plurality of directional vectors on the nodes of the triangulation by assigning the plurality of directional vectors, respectively, to the plurality of nodes of the triangulation, each of the directional vectors being assigned to a different node of the triangulation and having a direction.

A method of generating a set of simulation results which are adapted to be recorded or displayed on a recordation or display apparatus, comprising the steps of:

• (a) placing a boundary around a set of fault intersection lines on a horizon of an earth formation;
• (b) generating a structured areal grid which is imposed over said boundary, said structured areal grid having intersections, the generating step (b) for generating a structured areal grid including the step of building triangles of a triangulation over said boundary;
• (c) connecting coordinate lines to the intersections of said structured areal grid and performing vertical gridding wherein, after said vertical gridding, said coordinate lines intersect with another horizon of said earth formation thereby generating a structured simulation grid, said structured simulation grid including a plurality of grid blocks;
• (d) assigning properties to each grid block of said structured simulation grid thereby generating a simulation grid output wherein each of the plurality of grid blocks of said structured simulation grid have a property associated therewith;
• and
• (e) in response to the simulation grid output, assigning a simulation result to each grid block of said structured simulation grid thereby generating a plurality of simulation results wherein each of the plurality of grid blocks of said structured simulation grid have a simulation result associated therewith, said plurality of simulation results adapted to be recorded or displayed on said recordation or display apparatus.

A program storage device readable by a machine and tangibly embodying a program of instructions executable by the machine to perform method steps for generating a set of simulation results, said method steps comprising:

• (a) placing a boundary around a set of fault intersection lines on a horizon of an earth formation;
• (b) generating a structured areal grid and imposing said structured areal grid over said boundary, said structured areal grid having intersections, the generating step (b) for generating a structured areal grid including the step of building triangles of a triangulation over said boundary;
• (c) connecting coordinate lines to the intersections of said structured areal grid and performing vertical gridding wherein, after said vertical gridding, said coordinate lines intersect with another horizon of said earth formation thereby generating a structured simulation grid, said structured simulation grid including a plurality of grid blocks;
• (d) assigning properties to each grid block of said structured simulation grid thereby generating a simulation grid output wherein each of the plurality of grid blocks of said structured simulation grid have a property associated therewith;
• and
• (e) in response to the simulation grid output, assigning a simulation result to each grid block of said structured simulation grid thereby generating a plurality of simulation results wherein each of the plurality of grid blocks of said structured simulation grid have a simulation result associated therewith.